A port has begun "pioneering" work to allow cruise ships to plug into the National Grid.
Southampton is the first UK commercial port to install shore power facilities for cruise ships, owner Associated British Ports (ABP) said.
It will be available at two of the city's five cruise terminals from spring 2022, the firm added.
The port said shore power would improve air quality by reducing the amount of time ships run their engines in port.
ABP previously pledged to install the technology in 2020, adding that it was working on issues over funding and a sufficient supply of power.
It said the facilities at the Mayflower and Horizon terminals would be partly paid for by Solent Local Enterprise Partnership (LEP), which allocates government funding.
Only one of the charging points will operate at a time to avoid an excessive drain on power in Southampton, the firm said.
The firm said shore power could save up to 863kg of carbon dioxide and 10.5kg of nitrogen oxide (NOx) emissions per vessel call each year.
Mr Welch said: "This is good news for the port, for air quality and for the future of cruise."
However a report to Southampton councillors in January 2019 said shore power "demonstrated no discernible benefit to nitrogen dioxide concentrations at EU relevant locations".
Anne-Marie Mountifield, the LEP's chief executive, said: "Southampton's shore power initiative is a huge opportunity to pioneer the green credentials of our local economy."
Shore power - or "cold ironing" - is already available for cruise ships in the United States, Canada and some European ports.